With the rapid advance of electronic communication technologies, radio communication devices have become part of everyday activities. Such radio communication devices use radio frequency resources. Radio communication networks have evolved from the legacy radio and TV broadcasting networks to mobile communication networks for supporting voice and data communication services in various fields including satellite communication and military communication.
In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, the development focus has been on the 5th Generation (5G) or pre-5G communication system. For this reason, the 5G or pre-5G communication system is called a beyond 4G network communication system or post Long Term Evolution (LTE) system.
To accomplish higher data rates, consideration is being given to implementing the 5G communication system in millimeter wave (mmWave) frequency bands (e.g., 60 GHz bands). In order to increase the propagation distance by mitigating propagation loss in the 5G communication system, discussions are underway about various techniques such as beamforming, massive MIMO, Full Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna.
Also, in order to enhance network performance of the 5G communication system, developments are underway of various techniques such as evolved small cell, advanced small cell, cloud Radio Access Network (RAN), ultra-dense network, Device to Device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation.
Furthermore, the ongoing research includes the use of Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC) as Advanced Coding Modulation (ACM), Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA).
Meanwhile, it is predicted that the number of wireless radio communication devices will increase exponentially with the advent of the Internet of Things (IoT) and Machine Type Communication (MTC). The growing number of radio communication devices aggravates radio resource constraints, resulting in limitations on the data rate per device. In order to prepare for such situations, there is increasing demand for a higher data rate in the wireless communication network.
The simplest way of providing services at higher data rates would be to consider extending the available frequency band of the radio communication network; however, in order to extend the available frequency band it is necessary to reallocate frequency bands for the different radio communication technologies, and frequency band reallocation has reached an unrealizable point.
The mobile communication technology is migrating from the 3rd Generation (3G) to the 4th Generation (4G) technology. However, as described above, there may be realization soon that the 4G mobile communication technology cannot accommodate both the increasing number of radio communication devices and higher data rate requirements.
There is therefore a need of a multiple access technology that is more efficient than the current Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) in the beyond-4G mobile communication technology.
The aforementioned FBMC is one of the technologies capable of meeting the above requirements. The FBMC system adopts the OFDM scheme without use of Cyclic Prefix (CP). The FBMC system is capable of protecting against bandwidth waste caused by use of CP in the legacy OFDM system. The FBMC system is characterized by a high frequency confinement with per-subcarrier filtering, and this make it possible to expect a large gain by reducing the intra- and inter-communication band guard periods. In particular, the FBMC system may maximize gains in the case of supporting a large number of users or devices.
Meanwhile, a multicarrier system incurs multi-signal overlapping in the time domain because of signal splitting in the frequency domain, and the multi-signal overlapping in the time domain increases the Peak to Average Power Ratio (PAPR). Clipping and Precoding are promising methods proposed for reducing the PAPR in the multicarrier-based radio communication system. However, such methods have a drawback in terms of distorting the frequency spectrum characteristics and thus making it difficult to preserve the advantages of the FBMC system.